fix(runtime): recover OpenCode context after failed starts

[hopeatina]

Summary

• claim staged Wizard context before remote hydration, including chat-message-first ordering
• deliver bounded context only on the user message, avoiding title and small-model system transforms
• retry delivery after pre-inference failures, then stop after proven assistant or tool work
• atomically release unused interactive activations through the Wizard SessionAbandoned contract
• keep Gateway runtime sessions off the claim-capable SessionStart path so unrelated cwd-only activations cannot be consumed or misattributed
• clear Gateway-scoped failures without requeueing dispatch context
• canonicalize POSIX symlink aliases so Wizard and plugin agree on the exact cwd
• prepare @useorgx/orgx-opencode-plugin 0.1.0-alpha.19

Dependency

• Depends on hopeatina/orgx-wizard#116 at 539910f43134b2db74dc30897d448e3ec0d2780e.
• Wizard 0.1.79 must merge and publish before this plugin is released because it supplies OpenCode SessionStart context and the exact-owner SessionAbandoned recovery result.
• Wizard PR #116 currently has a blocking activation race under repair. Do not merge or publish alpha.19 until that dependency is fixed and green.
• This PR does not merge or publish either package.

Verification

• npm run type-check
• npm test: 13 Vitest files / 139 tests plus 9 Node tests passed
• npm run build
• npm pack --dry-run --json: alpha.19, 89,864-byte tarball, 87 entries
• npm registry readback before the bump: alpha tag was alpha.18 and alpha.19 was unused
• focused recovery suite covers chat-message-first claim, Gateway no-claim precedence, bounded delivery, provider-auth failure, fail-closed release, successful consumption, missing native idle, unpersisted consumption with exact cleanup, tool use, and Gateway cleanup

Rollout and remaining proof

• No hosted data, user config, merge, or package publish was performed.
• An OpenCode 1.16.2 diagnostic proved user-message system context reaches the main model while the experimental system transform also runs for title and small-model calls. That diagnostic validated the delivery surface, not this packaged branch end to end.
• After the Wizard dependency is fixed, Wizard 0.1.79 and this alpha.19 package are published, install both on a disposable actual-host profile and rerun the successful and ProviderAuthError canaries before promoting the alpha tag.